Capacitive Contact and Actuation Detection with Shared Electrodes
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Solution Overview
Problem
Existing capacitive contact and actuation detection systems require separate electrodes and electronic circuits, leading to high design complexity and electronic evaluation system requirements, making it difficult to distinguish between contact and actuation effectively.
Innovation Solution
A method using a capacitive sensor with a single sensor electrode and a common counter electrode, applying different electric potentials to distinguish between contact and actuation by calculating and comparing parameters derived from measured charge transfers, reducing the number of electrodes and electronic inputs needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate electrodes and electronic circuits are used for contact and actuation detection, then detection reliability is improved, but device complexity increases
Solution Approach 1:
The patent combines contact detection and actuation detection into a single capacitive sensor system using one sensor electrode and one counter electrode. By applying different evaluation methods to the same electrode pair, the system distinguishes between contact (light touch) and actuation (pressing) without requiring separate detection devices, thereby reducing device complexity while maintaining detection reliability
Solution Approach 2:
The single capacitive sensor system performs multiple functions: it detects both contact and actuation events using the same electrode configuration. The counter electrode and sensor electrode pair serves dual purposes by evaluating different capacitive effects under different operating conditions, making the detection system universal for both detection modes
2Measurement precision
If multiple electrodes and measurement inputs are used, then measurement precision is improved, but electronic evaluation system complexity increases
Solution Approach 1:
The patent changes the evaluation parameters of the same electrode pair to distinguish between contact and actuation. By monitoring different capacitive characteristics (capacitance changes, charge transfer patterns, time constants) from the single sensor electrode and counter electrode combination, the system achieves precise differentiation of detection modes without adding more electrodes or measurement inputs
Solution Approach 2:
The system dynamically evaluates capacitive measurements based on the detection mode. Different evaluation algorithms are applied depending on whether contact or actuation is detected, allowing the electronic evaluation system to adapt its measurement strategy and maintain precision while working with a fixed, minimal electrode configuration
3Measurement precision
If different detection devices are used for contact and actuation, then detection accuracy is improved, but ease of manufacture decreases
Solution Approach 1:
The patent merges contact detection and actuation detection into a single integrated capacitive sensor unit. The same sensor electrode and counter electrode structure serves both detection purposes, simplifying the manufacturing process by eliminating the need to produce, assemble, and calibrate separate detection devices while maintaining the ability to accurately distinguish between contact and actuation events
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach simplifies the design and electronic evaluation system, allowing for reliable differentiation between contact and actuation using a single sensor electrode and counter electrode, reducing the complexity and resources required for detection.
Implementation Method 1
capacitive contact and actuation detection
Implementation Method 2
a first capacitive measuring field between the sensor electrode and the counter electrode
Data Source
AI summary
The embodiments disclosed herein relate to a method for the capacitive detection of at least a contact of a capacitive sensor by an operator. The method includes providing the capacitive sensor and providing an electronic evaluation system; applying a first constant electric potential to the counter electrode of the capacitive sensor; applying a second constant electric potential, which differs from the first potential, to the counter electrode of the capacitive sensor; calculating a first parameter from the first measured value and the second measured value; calculating a second parameter from the first measured value and the second measured value; and respectively comparing the first parameter and the second parameter with a predefined quantity.